Thermal and non-thermal processing affect Maillard reaction products, flavor, and phytochemical profiles of Ginkgo biloba seed

Works of literature focused on the standardization of Ginkgo biloba extract from the dried ginkgo leaves, and little research has been done on ginkgo seed as a functional food and a nutraceutical. Drying can have beneficial effects on phytochemicals, flavor as well as improving their bio-accessibility or modifying chemical structures to enhance absorption. In this study, Ginkgo biloba seed (GBS) was dehydrated using non-thermal (freeze-drying) and thermal (infrared-drying, hot-air drying, pulsed-vacuum drying) processing. A comparative analysis were performed using UV–Vis spectrophotometer, fluorescence spectrophotometer, Fourier transform infrared spectroscopy (FTIR), gas chromatography-tandem mass spectroscopy (GC-MS/MS), and electronic nose (E-nose). Results showed drying methods had a significant influence on Maillard reaction products, flavor, and phytochemical profiles, while FTIR analysis showed drying methods did not change preliminary structures. GC-MS/MS showed many phytoconstituents that led to a better appreciation of nutraceutical, pharmaceutical, and medicinal benefits. These compounds consist of fatty alcohol, long-chain alkanes, fatty acids, carboxylic acid, sterols, diterpenes, triterpenes, flavonoids, and their derivatives. The infrared-dried GBS had the highest (61) phytoconstituent, while pulsed-vacuum dried ginkgo seeds the least (24). Electronic nose differentiated flavor intensity of dried ginkgo seed, with freeze-drying exhibiting the least intensity. The principal component analysis combined with GC-MS/MS and E-nose differentiated samples and was attested by Hierarchical cluster analysis. Infrared-dried product was superior with the highest Maillard reaction (highest A294 and A420). These data will provide vital information for selecting a befitting drying method for ginkgo seed processing and GBS application as a nutraceutical.